﻿using System;
using System.Text.RegularExpressions;

namespace Common.Library
{
    /// <summary>
    /// 数字帮助类
    /// </summary>
    public static class NumeralHelper
    {
        /// <summary>   
        /// 生成小于输入值绝对值的随机数   
        /// </summary>   
        /// <param name="NumSides"></param>   
        /// <returns></returns>   
        public static int Next(this int numSeeds)
        {
            numSeeds = Math.Abs(numSeeds);
            if (numSeeds <= 1)
            {
                return 0;
            }

            int length = 4;
            if (numSeeds <= byte.MaxValue)
            {
                length = 1;
            }
            else if (numSeeds <= short.MaxValue)
            {
                length = 2;
            }

            return Next(numSeeds, length);
        }

        private static int Next(int numSeeds, int length)
        {
            // Create a byte array to hold the random value.   
            byte[] buffer = new byte[length];
            // Create a new instance of the RNGCryptoServiceProvider.   
            System.Security.Cryptography.RNGCryptoServiceProvider Gen = new System.Security.Cryptography.RNGCryptoServiceProvider();
            // Fill the array with a random value.   
            Gen.GetBytes(buffer);
            // Convert the byte to an uint value to make the modulus operation easier.   
            uint randomResult = 0x0;//这里用uint作为生成的随机数   
            for (int i = 0; i < length; i++)
            {
                randomResult |= ((uint)buffer[i] << ((length - 1 - i) * 8));
            }
            // Return the random number mod the number   
            // of sides.  The possible values are zero-based   
            return (int)(randomResult % numSeeds);
        }

        /// <summary>
        /// 金额转中文
        /// </summary>
        /// <param name="number"></param>
        /// <returns></returns>
        public static String ConvertToChinese(Decimal number)
        {
            var s = number.ToString("#L#E#D#C#K#E#D#C#J#E#D#C#I#E#D#C#H#E#D#C#G#E#D#C#F#E#D#C#.0B0A");
            var d = Regex.Replace(s, @"((?<=-|^)[^1-9]*)|((?'z'0)[0A-E]*((?=[1-9])|(?'-z'(?=[F-L\.]|$))))|((?'b'[F-L])(?'z'0)[0A-L]*((?=[1-9])|(?'-z'(?=[\.]|$))))", "${b}${z}");
            var r = Regex.Replace(d, ".", m => "负元空零壹贰叁肆伍陆柒捌玖空空空空空空空分角拾佰仟万亿兆京垓秭穰"[m.Value[0] - '-'].ToString());
            return r;
        }

        /// <summary>
        /// 金额转换成中文大写金额
        /// </summary>
        /// <param name="LowerMoney">eg:10.74</param>
        /// <returns></returns>
        public static string MoneyToUpper(string LowerMoney)
        {
            string functionReturnValue = null;
            bool IsNegative = false; // 是否是负数
            if (LowerMoney.Trim().Substring(0, 1) == "-")
            {
                // 是负数则先转为正数
                LowerMoney = LowerMoney.Trim().Remove(0, 1);
                IsNegative = true;
            }
            string strLower = null;
            string strUpart = null;
            string strUpper = null;
            int iTemp = 0;
            // 保留两位小数 123.489→123.49　　123.4→123.4
            LowerMoney = Math.Round(double.Parse(LowerMoney), 2).ToString();
            if (LowerMoney.IndexOf(".") > 0)
            {
                if (LowerMoney.IndexOf(".") == LowerMoney.Length - 2)
                {
                    LowerMoney = LowerMoney + "0";
                }
            }
            else
            {
                LowerMoney = LowerMoney + ".00";
            }
            strLower = LowerMoney;
            iTemp = 1;
            strUpper = "";
            while (iTemp <= strLower.Length)
            {
                switch (strLower.Substring(strLower.Length - iTemp, 1))
                {
                    case ".":
                        strUpart = "圆";
                        break;
                    case "0":
                        strUpart = "零";
                        break;
                    case "1":
                        strUpart = "壹";
                        break;
                    case "2":
                        strUpart = "贰";
                        break;
                    case "3":
                        strUpart = "叁";
                        break;
                    case "4":
                        strUpart = "肆";
                        break;
                    case "5":
                        strUpart = "伍";
                        break;
                    case "6":
                        strUpart = "陆";
                        break;
                    case "7":
                        strUpart = "柒";
                        break;
                    case "8":
                        strUpart = "捌";
                        break;
                    case "9":
                        strUpart = "玖";
                        break;
                }

                switch (iTemp)
                {
                    case 1:
                        strUpart = strUpart + "分";
                        break;
                    case 2:
                        strUpart = strUpart + "角";
                        break;
                    case 3:
                        strUpart = strUpart + "";
                        break;
                    case 4:
                        strUpart = strUpart + "";
                        break;
                    case 5:
                        strUpart = strUpart + "拾";
                        break;
                    case 6:
                        strUpart = strUpart + "佰";
                        break;
                    case 7:
                        strUpart = strUpart + "仟";
                        break;
                    case 8:
                        strUpart = strUpart + "万";
                        break;
                    case 9:
                        strUpart = strUpart + "拾";
                        break;
                    case 10:
                        strUpart = strUpart + "佰";
                        break;
                    case 11:
                        strUpart = strUpart + "仟";
                        break;
                    case 12:
                        strUpart = strUpart + "亿";
                        break;
                    case 13:
                        strUpart = strUpart + "拾";
                        break;
                    case 14:
                        strUpart = strUpart + "佰";
                        break;
                    case 15:
                        strUpart = strUpart + "仟";
                        break;
                    case 16:
                        strUpart = strUpart + "万";
                        break;
                    default:
                        strUpart = strUpart + "";
                        break;
                }

                strUpper = strUpart + strUpper;
                iTemp = iTemp + 1;
            }

            strUpper = strUpper.Replace("零拾", "零");
            strUpper = strUpper.Replace("零佰", "零");
            strUpper = strUpper.Replace("零仟", "零");
            strUpper = strUpper.Replace("零零零", "零");
            strUpper = strUpper.Replace("零零", "零");
            strUpper = strUpper.Replace("零角零分", "整");
            strUpper = strUpper.Replace("零分", "整");
            strUpper = strUpper.Replace("零角", "零");
            strUpper = strUpper.Replace("零亿零万零圆", "亿圆");
            strUpper = strUpper.Replace("亿零万零圆", "亿圆");
            strUpper = strUpper.Replace("零亿零万", "亿");
            strUpper = strUpper.Replace("零万零圆", "万圆");
            strUpper = strUpper.Replace("零亿", "亿");
            strUpper = strUpper.Replace("零万", "万");
            strUpper = strUpper.Replace("零圆", "圆");
            strUpper = strUpper.Replace("零零", "零");

            // 对壹圆以下的金额的处理
            if (strUpper.Substring(0, 1) == "圆")
            {
                strUpper = strUpper.Substring(1, strUpper.Length - 1);
            }
            if (strUpper.Substring(0, 1) == "零")
            {
                strUpper = strUpper.Substring(1, strUpper.Length - 1);
            }
            if (strUpper.Substring(0, 1) == "角")
            {
                strUpper = strUpper.Substring(1, strUpper.Length - 1);
            }
            if (strUpper.Substring(0, 1) == "分")
            {
                strUpper = strUpper.Substring(1, strUpper.Length - 1);
            }
            if (strUpper.Substring(0, 1) == "整")
            {
                strUpper = "零圆整";
            }
            functionReturnValue = strUpper;

            if (IsNegative == true)
            {
                return "负" + functionReturnValue;
            }
            else
            {
                return functionReturnValue;
            }
        }
    }
}
